You should keep the black one if only for date nights with your SO. Go on, it is just gorgeous on you.

Oh, I wish I looked half as good as you do in dresses! You look gorgeous in both. I saw that black one online and drooled over it, and I think you wear it extremely well. I don't see overly body-con at all, but I think black really helps to make a bodycon cut look slim but not tight.